follow RFC-6120 section 6.4.4: send <abord> and a SASL authentication mechanism fails, wait for server <failure> reply before trying a new mechanism

src/common/xmpp/auth_nb.py

@@ -49,6 +49,7 @@ except ImportError:
 
 GSS_STATE_STEP = 0
 GSS_STATE_WRAP = 1
+SASL_FAILURE_IN_PROGRESS = 'failure-in-process'
 SASL_FAILURE = 'failure'
 SASL_SUCCESS = 'success'
 SASL_UNSUPPORTED = 'not-supported'
@@ -285,15 +286,20 @@ class SASL(PlugIn):
         ### Handle Auth result
         def on_auth_fail(reason):
             log.info('Failed SASL authentification: %s' % reason)
+            self._owner.send(str(Node('abort', attrs={'xmlns': NS_SASL})))
             if len(self.mecs) > 0:
-                # There are other mechanisms to test
-                self.MechanismHandler()
+                # There are other mechanisms to test, but wait for <failure>
+                # answer from server
+                self.startsasl = SASL_FAILURE_IN_PROGRESS
                 raise NodeProcessed
             if self.on_sasl:
                 self.on_sasl()
             raise NodeProcessed
 
         if challenge.getName() == 'failure':
+            if self.startsasl == SASL_FAILURE_IN_PROGRESS:
+                self.MechanismHandler()
+                raise NodeProcessed
             self.startsasl = SASL_FAILURE
             try:
                 reason = challenge.getChildren()[0]